Various apparatus for sharpening circular blades are known in the art. For example, U.S. Pat. No. 2,528,193 to Van Allen et al. entitled “Automatic Disk Blade Grinder” discloses a machine for grinding disk-type blades that is adjustable and power-operated for grinding the edge of a disk-type blade to a predetermined bevel and throughout the entire circumference of the blade.
In an apparatus for sharpening a circular blade, the part of the apparatus that holds the circular blade may be angularly adjustable in relation to the sharpening wheel. This is because circular blades having different circumferences require different angular positioning in relation to the power-driven sharpening wheel to ensure uniform sharpening, and a user wants to be able to use the same sharpening apparatus to sharpen circular blades of many different sizes.
Also, a sharpening apparatus for circular blades needs to be safe. A user engaged in blade sharpening attempts to sharpen circular blades as quickly and efficiently as possible, but circular blades are very sharp, requiring the user to take special precautions. Specifically, precautions should be taken when loading the blade onto the sharpening apparatus, when running the power-driven sharpening wheel during sharpening, and when removing the blade from the sharpening apparatus.
Additionally, the moving parts of a circular blade sharpening apparatus should be easy to manipulate so that a user can sharpen circular blades in an efficient manner. For example, if a user wants to sharpen one side of a two-sided circular blade and immediately switch to sharpening the other side of the blade, a sharpening apparatus should be provided with a blade holder or a blade loading and release mechanism that easily enables the user to remove the blade, turn it over, and quickly begin sharpening the second side.
Thus, a need exists in the art for a sharpening apparatus for circular blades wherein the moving parts of the apparatus are easy to manipulate so that the circular blade may be loaded onto and removed from the sharpening apparatus quickly and efficiently. A further need exists for a sharpening apparatus that is safe, where the user's hands and fingers come into contact with the blade as little as possible. The sharpening apparatus of the present invention addresses these and other needs.